Both these portions of the instrument must be made of ebony (Fig. 12). Before the finger-board is glued, the surfaces to be joined must be made particularly smooth. The length is 268 m/m. in an instrument of normal size, and in those which are longer and shorter, the necessary proportion is easily determined. The width of the upper end, near the nut, is 24 m/m., while at the lower end it measures 45 m/m.
The curve at the nut should be the same as the curve of the bridge, the thickness being from 4 to 5 m/m. Whilst the centre of the finger-board should form a straight line lengthways, it must be hollowed out under the E-string equally to the depth of 1 m/m., and under the G-string to 1¹⁄₂ m/m., in order to prevent the jarring and rattling of the strings. The thickness of the nut must be 5 m/m. on the under side and 4 m/m. on the upper. The distance between the two outer string-grooves must be from 16 to 18 m/m. The strings lie at the nut (a) in the case of E, A, and D-strings at a distance of ¹⁄₂ m/m. from the finger-board, the G-string 1 m/m. The thickness of the neck, including the finger-board, is 18 m/m. at the upper curve (Fig. 8b I.) for a hand of ordinary size, and 24 m/m. at the lower curve (Fig. 8b II); but this thickness can be altered according to the wish of the performer.
XIV. THE POSITION OF THE NECK.
The neck of the violin must be regulated according to the width of the finger-board. It must be cut about 7 m/m. longer than the length required, when in position, in order to allow for its insertion in the block; the entire length of the neck from the nut to the end should measure 135 m/m. When this has been duly arranged, the neck can be fitted into the block. The small semi-circular elongation of the back of the violin, in common with the upper block, serves principally to support the neck and keep it in position, at the same time giving the performer a correct hold.
The finger-board having been glued to the neck, it is of the utmost importance that the latter should be fitted in very carefully, so that it protrude 5 m/m. from the belly (Fig. 8e).
If the gauge be placed on the centre of the finger-board in the line a a (Fig. I and II), the end a (Fig. 9, third plate) should fall exactly on the line of connection between the innermost excisions of the F-holes, having its centre under the place where the bridge stands, so that the finger-board may exactly coincide with the measure.
This arrangement gives us not only the correct position of the finger-board, but also, as we shall see later on, the right height of the bridge, 35 m/m., and also the suitable position of the strings according to their height. The measurement marked upon the gauge (Fig. 9), viz.: from a (beginning of the nut) as far as the upper edge of the belly b (end of the neck) and thence to a (place of the bridge) must be in such proportion to one another as to give the violin practical dimensions and height of bridge.
XV. THE TAIL-PIECE (Fig. 11).
This part of the instrument exercises a great influence on the tone, although the fact is doubted by a great many performers. I will endeavour to briefly demonstrate my idea upon the subject. In the first place, I would remark in reference to the shape and size of the tail-piece that the upper curve must resemble the curve of the bridge.
The semi-circular ridge at the upper end is called the saddle and must project about 1 m/m. The upper and movable end of the tail-piece is not arranged at right angles with the middle line of the same, but inclines about 1¹⁄₂ m/m. towards the G-string. This is done in order to balance, so to speak, the crooked position of the tail-piece which has been occasioned by the greater tension of the E-string in comparison with the G-string, and also to keep the upper edge of the tail-piece parallel with the upper edge of the bridge, which is very necessary to the elegant appearance of the lower portion of the violin. The space between the incisions for G and E-strings should be 30 m/m. The length of the strings below the bridge from the upper edge of the same to the saddle on the tail-piece should be 55 m/m., and then the A-string behind the bridge will give the high E. If the proportion of the tail-piece to the bridge be changed, that is to say, lengthened or shortened by the use of a larger or smaller tail-piece with the same length of the tail-piece fastener, the tension of the strings also becomes altered, and the tone and vibrations are thereby affected.